A temperature inversion in "Chinese Arctic Research Expedition 1999

1　ＩｎｔｒｏｄｕｃｔｉｏｎＴｈｅＡｒｃｔｉｃａｒｅａ ,ａｓｔｈｅｂａｃｋｇｒｏｕｎｄｏｆｇｌｏｂａｌｃｌｉｍａｔｅａｎｄｅｎｖｉｒｏｎｍｅｎｔ,ｄｒａｗｓｐｅｏ ｐｌｅ’ｓａｔｔｅｎｔｉｏｎｗｉｔｈｉｔｓｉｍｐａｃｔｏｎｇｌｏｂａｌｃｈａｎｇｅ (ＩＰＣＣ 1 990 ) .Ｇｒｅａｔａｍｏｕｎｔｏｆｅｎｅｒｇｙａｎｄｍａｓｓａｒｅｅｘｃｈａｎｇｅｄｂｅｔｗｅｅｎｔｈｅｓｅａａｎｄａｉｒｗｉｔｈｓｐｅｃｉａｌｉｎｔｅｒｆａｃｅ,ａｉｒ ｉｃｅ ｓｅａｓｕｒｆａｃｅ ,ｉｎｔｈｉｓａｒｅａ .Ｔｈｅｒｅｆｏｒｅｉｔｉ…     

Finite element analysis of land subsidence above depleted reservoirs with pore pressure gradient and total stress formulations

The solution of the poroelastic equations for predicting land subsidence above productive gas/oil fields may be addressed by the principle of virtual works using either the effective intergranular stress, with the pore pressure gradient regarded as a distributed body force, or the total stress incorporating the pore pressure. In the finite element (FE) method both approaches prove equivalent at the global assembled level. However, at the element level apparently the equivalence does not hold, and the strength source related to the pore pressure seems to generate different local forces on the element nodes. The two formulations are briefly reviewed and discussed for triangular and tetrahedral finite elements. They are shown to yield different results at the global level as well in a three‐dimensional axisymmetric porous medium if the FE integration is performed using the average element‐wise radius. A modification to both formulations is suggested which allows to correctly solve the problem of a finite reservoir with an infinite pressure gradient, i.e. with a pore pressure discontinuity on its boundary. Copyright © 2001 John Wiley & Sons, Ltd.     

RELATION BETWEEN δ~（18）O IN ATMOSPHERIC PRECIPITATION AND TEMPERATURE AND PRECIPITATION

ＲＥＬＡＴＩＯＮＢＥＴＷＥＥＮδ~（１８）ＯＩＮＡＴＭＯＳＰＨＥＲＩＣＰＲＥＣＩＰＩＴＡＴＩＯＮＡＮＤＴＥＭＰＥＲＡＴＵＲＥＡＮＤＰＲＥＣＩＰＩＴＡＴＩＯＮＺｈａｎｇＸｉｎｐｉｎｇ（章新平）（ＤｅｐａｒｔｍｅｎｔｏｆＧｅｏｇｒａｐｈｙ，ＨｕｎａｎＮｏ?..     

The effects of temperature and substrate on ontogenetic behavior of bastard halibut, Paralichthys olivaceus (T. et S.)

1 INTRODUCTION Scientific management of aquacultural andnatural populations studies on the early life historyof flatfishes in the aspects of their metamorphosisand benthic settlement accompanying pronouncedtransitions in morphology, behavior and habitatecology have received much attention (Youson,1988). Accumulated data showed that temperatureand substrate played a main role in the recruitmentsuccess of flatfish during their early development(Rijnsdorp et al., 1995, Gibson and Robb, 2000…     

Parameters affect foaming and foam stability during foam drilling

The authors presented indoor practice experiments of parameters affect on foaming and foam stability. Experiments were carried out and special equipments were used to determine foaming and foam stability; tests were tabulated and charted. The effects of chemical and physical parameters on foaming and foam stability have been conducted.     

Hydrogeologic controls on summer stream temperatures in the McKenzie River basin,Oregon

Stream temperature is a complex function of energy inputs including solar radiation and latent and sensible heat transfer. In streams where groundwater inputs are significant, energy input through advection can also be an important control on stream temperature. For an individual stream reach, models of stream temperature can take advantage of direct measurement or estimation of these energy inputs for a given river channel environment. Understanding spatial patterns of stream temperature at a landscape scale requires predicting how this environment varies through space, and under different atmospheric conditions. At the landscape scale, air temperature is often used as a surrogate for the dominant controls on stream temperature. In this study we show that, in regions where groundwater inputs are key controls and the degree of groundwater input varies in space, air temperature alone is unlikely to explain within-landscape stream temperature patterns. We illustrate how a geologic template can offer insight into landscape-scale patterns of stream temperature and its predictability from air temperature relationships. We focus on variation in stream temperature within headwater streams within the McKenzie River basin in western Oregon. In this region, as in other areas of the Pacific Northwest, fish sensitivity to summer stream temperatures continues to be a pressing environmental issue. We show that, within the McKenzie, streams which are sourced from deeper groundwater reservoirs versus shallow subsurface flow systems have distinct summer temperature regimes. Groundwater streams are colder, less variable and less sensitive to air temperature variation. We use these results from the western Oregon Cascade hydroclimatic regime to illustrate a conceptual framework for developing regional-scale indicators of stream temperature variation that considers the underlying geologic controls on spatial variation, and the relative roles played by energy and water inputs. Copyright © 2007 John Wiley & Sons, Ltd.     

南极洛多姆冰帽BJ钻孔粒雪层的热学性质及其温度分布

根据详细的密度资料,对洛多姆冰帽BJ钻孔粒雪层的热学性质进行了讨论。应用非均匀介质热传导方程描述活动层温度分布。通过两种简化的层状结构和竖向运动模型给出了解析解。计算和实测温度差异的分析表明边界条件的选取非常重要。     

COMBINATION OF ECMWF REANALYZED DAILY RAINFALL AND PENTAD CMAP IN CHINA

In this study, 16 combinations of the ECMWF (European Centre for Medium-Range Weather Forecast) reanalyzed daily rainfall and the pentad CMAP in China for the period 1980- 1993( 1May - 31 Dec. ) were calculated. Correlation analysis was used to roughly evaluate daily rainfall for the whole of China and a combination of RPC (rotated principal component) and wavelet analyses was applied to data on observed and combined daily rainfall to obtain a detailed evaluation of the quality of these combined datasets in 6 selected major rainfall regions of eastern China. The results showed that except for intraweekly fluctuation, the best combination was roughly similar to or accorded well with observation in the aspects of space variation patterns and long period rainfall fluctuations related to monsoon onset and serious meteorologic disasters, indicating that this combination yielded better values of long term daily mean and standard deviation through the pentad CMAP ( CPC Merged Analysis of Precipitation), and can also represent rainfall fluctuations through the reanalyzed daily rainfall.     

长期天气变化与地球自转速度的若干关系

本文应用1820—1983年的地球自转变化率资料,分析出地球自转变化存在准44个月、准11年、准24年和准49年的周期。南方涛动指数的变化,大气活动中心位置的移动,赤道东太平洋海温的异常等,都能从地球自转速度变化思期中找到关系。已经发现,在地转长期(准24年和准49年周期)加(减)速时,南方涛动指数减弱(增强),大气活动中心向西北(东南)移动,非洲干旱区降水偏多(偏少);同时发现:在地转短期(准44个月周期)加(减)速时,赤道东太平洋海温降低(升高)。本文讨论微机在地理学上的应用,介绍可以从英美市场获得的地理软件,并检讨微机在英美地理教学和研究上的一些限制,以促进其在国内地理学上的应用。现存的软件和硬件基本上可以满足地理教学和研究上的大部分需要。随着微机价格的降低,体积的缩小,计算速度、内外存储器容量以及可携带性的增加,其实际应用将会更广。微机已逐渐成为地理教学和研究中不可缺少的工具。